1. Field of the Invention
The invention relates to a method of motion detection in an interlaced television picture obtained after film-to-television conversion, the method being based on picture signal comparison between picture elements in consecutive television pictures which are assembled line and field-sequentially in frame periods consisting of two field periods, in the method, starting from a picture element in the television picture the picture signal value thereof being compared with those of a corresponding picture element in the preceding and the subsequent television picture and with those of a number of surrounding picture elements, motion or no motion, respectively, being determined in dependence on the fact whether comparison results exceed or do not exceed a threshold value.
The invention also relates to an arrangement suitable for performing such a method.
2. Description of the Related Art
Motion detection can be utilized for various purposes. For a television transmission channel having a bandwidth which is more limited than the bandwidth of the television signal source, the motion detection can be used for a bandwidth reduction of the signal to be transmitted. During television signal conversion from one standard to another, the motion detection can be used to provide an improved picture quality on display of the converted picture signal.
When the television signal source includes a film-to-television converter (telecine), the specific structure of the picture signal can then be used for an optimum motion detection since it is a known technique to convert 24 movie picture frames per second into 25 or 30 interlaced television pictures or frames per second, by coupling the television pictures to the film frames, so that picture information changes between consecutive film frames can only occur between predetermined television pictures. In the case of single interlace using two fields per television picture or frame, the picture information components per two fields are always identical.